浸渍方法对“蛇龙珠”葡萄酿酒过程及葡萄酒中IBMP的影响

Effects of Impregnation Method on Winemaking Process and IBMP in"Gernischt"Grape Wine

建立了顶空固相微萃取结合气相色谱-质谱仪(HS-SPME-GC-MS)测定葡萄酒中3-异丁基-2-甲氧基吡嗪(IBMP)质量浓度的检测方法。经优化,确定HS-SPME最佳条件为40℃预挥发15 min,HS-SPME萃取30 min,解吸3 min。IBMP在2~500 ng·L^(-1)的线性范围内,相关系数为0.9996,葡萄酒中的添加回收率为76%~109%,相对标准偏差为2.0%~6.5%。该方法线性良好、准确、精密度高。以宁夏银川产区“蛇龙珠”葡萄为酿造原料,分别采用传统浸渍、冷浸渍、热浸渍法酿酒,对酿酒过程和葡萄酒中IBMP质量浓度进行测定分析。结果表明,浸渍3 d时葡萄汁中IBMP质量浓度最高,随浸渍时间延长,其含量呈下降趋势,酒精发酵过程中IBMP质量浓度趋于稳定;葡萄酒中IBMP质量浓度由大到小依次为冷浸渍法、传统浸渍法、热浸渍法,浸渍方法对IBMP质量浓度有显著影响。浸渍方法间的差异主要体现在温度的不同,可以确定浸渍的温度是影响葡萄酒中IBMP质量浓度的重要因素之一。

A method for the determination of 3-isobutyl-2-methoxypyrazine(IBMP)in wine was established by headspace solid phase microextraction combined with gas chromatography-mass spectrometer(HS-SPME-GC-MS).After optimization,the optimal conditions of HS-SPME were determined as prevolatilization at 40℃for 15 min,extraction by HS-SPME for 30 min,and desorption for 3 min.The linear range of IBMP was 2~500 ng·L^(-1),the correlation coefficient was 0.9996,the recoveries of IBMP in wine were 76%~109%with RSD of 2.0%~6.5%.The method has good linearity,accuracy and high precision.Winemaking process and IBMP content of"Gernischt"grape in Yinchuan region of Ningxia were determined by traditional method,cold impregnation method and hot impregnation method.The results showed that the IBMP content in grape juice was the highest when impregnated for 3 days,and decreased with the extension of impregnation time,and the IBMP content tended to be stable during alcoholic fermentation.The IBMP content in wine was as follows:cold impregnation>traditional impregnation>hot impregnation,and the impregnation method had a significant effect on IBMP content.According to the difference of impregnation methods mainly reflected in the difference of temperature,it can be determined that the impregnation temperature is one of the important factors affecting the content of methoxypyrazine in wine.